Version 1.14.17 introduces the getRecentPrioritizationFees RPC API, referencing the “priority” fees requested and returned via the ComputeBudget::SetComputeUnitPrice instruction. The endpoint returns a list of priority fees over the last 150 blocks that was used to successfully land at least one transaction with matching input parameters. The endpoint takes the optional argument of an array of accounts. If no accounts are provided, it matches any transaction. If an array of accounts is provided, it matches against any transactions that specified all of the provided accounts as writable. Developers may read the associated API docs in full detail here.
This API is provided so clients can use the data to estimate with what percentage likelihood and what priority fee is currently needed to land a transaction, or a transaction with a particular writable account set. This is useful for wallets or dApps wishing to take full advantage of the localized fee markets that the introduction of priority fees made possible on Solana.